Optical imaging system and portable electronic device

ABSTRACT

An optical imaging system includes a first lens, a second lens, a third lens, and a fourth lens disposed in order from an object side. The optical imaging system satisfies 4.0&lt;f/IMG_HT&lt;5.0, where f is a focal length of the optical imaging system, and IMG_HT is one-half of a diagonal length of an imaging plane.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application is a continuation of U.S. application Ser. No.17/004,254 filed on Aug. 27, 2020, which claims the benefit under 35 USC119(a) of Korean Patent Application No. 10-2019-0107271 filed on Aug.30, 2019 in the Korean Intellectual Property Office, the entiredisclosures of which are incorporated herein by reference for allpurposes.

BACKGROUND 1. Field

The following description relates to an optical imaging systemconfigured to fold an optical path.

2. Description of Related Art

In a collapsible optical imaging system in which a plurality of lensesis arranged linearly, a focal length of the optical system may increasewhen the number of lenses increases. For example, it may be difficult toreduce a size of an optical imaging system including four or morelenses. For this reason, there may be a limitation in mounting acollapsible optical imaging system having a relatively long focal lengthon a portable terminal device having a reduced thickness.

SUMMARY

This Summary is provided to introduce a selection of concepts insimplified form that are further described below in the DetailedDescription. This Summary is not intended to identify key features oressential features of the claimed subject matter, nor is it intended tobe used as an aid in determining the scope of the claimed subjectmatter.

An optical imaging system which may have a relatively long focal lengthand may be mountable on a small-sized terminal device having a reducedthickness.

In one general aspect, an optical imaging system includes a first lens,a second lens, a third lens, and a fourth lens disposed in order from anobject side. The optical imaging system satisfies 4.0<f/IMG_HT<5.0,where f is a focal length of the optical imaging system, and IMG_HT isone-half of a diagonal length of an imaging plane.

The optical imaging system may satisfy 0.10<L2R2/f<1.0, where L2R2 is aradius of curvature of an image-side surface of the second lens.

The optical imaging system may satisfy 0.10<(L2R1+L2R2)/(L2R1−L2R2)<1.0,where L2R1 is a radius of curvature of an object-side surface of thesecond lens, and L2R2 is a radius of curvature of an image-side surfaceof the second lens.

The optical imaging system may satisfy 1.0<f/f1<5.0, −5.0<f/f2<−1.0,−1.0<f/f3<3.0, and −5.0<f/f4<5.0, where f1 is a focal length of thefirst lens, f2 is a focal length of the second lens, f3 is a focallength of the third lens, and f4 is a focal length of the fourth lens.

The optical imaging system may include a first prism disposed on anobject side of the first lens.

The optical imaging system may satisfy 11 mm<PTTL<15 mm, where PTTL is adistance from a reflective surface of the first prism to the imagingplane.

The optical imaging system may satisfy 1.0 mm<DPL1<1.2 mm, where DPL1 isa distance from an image-side surface of the first prism to anobject-side surface of the first lens.

The optical imaging system may satisfy 1.0<PTTL/f<2.0, where PTTL is adistance from the reflective surface of the first prism to the imagingplane.

The optical imaging system may include a second prism disposed betweenthe fourth lens and the imaging plane.

In another general aspect, an optical imaging system includes a firstprism configured to emit light incident along a first optical axis in adirection of a second optical axis intersecting the first optical axis;a first lens having a convex image-side surface; a second lens having aconcave image-side surface; a third lens having refractive power; and afourth lens having a convex object-side surface. The first prism, thefirst lens, the second lens, the third lens, and the fourth lens aredisposed in order in the direction of the second optical axis. Theoptical imaging system satisfies 1.0<PTTL/f<2.0, where PTTL is adistance from a reflective surface of the first prism to an imagingplane, and f is a focal length of the optical imaging system.

The optical imaging system may satisfy 4.0<f/IMG_HT<5.0, where f is afocal length of the optical imaging system, and IMG_HT is one-half of adiagonal length of the imaging plane.

The first lens may have a convex object-side surface.

The second lens may have a concave object-side surface.

The third lens may have a convex object-side surface or a conveximage-side surface.

The optical imaging system may satisfy 0.10<L2R2/f<1.0, where L2R2 is aradius of curvature of an image-side surface of the second lens.

A portable electronic device may include three or more camera modules,wherein an optical axis of a first camera module is formed in adifferent direction from an optical axis of a second camera module andan optical axis of a third camera module, and the image sensor may beconfigured to convert light incident through the first to fifth lensesto an electrical signal.

The first camera module may have the narrowest angle of view and thelongest focal length, the third camera module may have the widest angleof view and the shortest focal length, and the second camera module mayhave a wider angle of view than the first camera module and a narrowerangle of view than the third camera module.

Other features and aspects will be apparent from the following detaileddescription, the drawings, and the claims.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a diagram illustrating a first example of an optical imagingsystem.

FIG. 2 shows aberration curves of the optical imaging system illustratedin FIG. 1 .

FIG. 3 is a diagram illustrating a second example of an optical imagingsystem.

FIG. 4 shows aberration curves of the optical imaging system illustratedin FIG. 3 .

FIG. 5 is a diagram illustrating a third example of an optical imagingsystem.

FIG. 6 shows aberration curves of the optical imaging system illustratedin FIG. 5 .

FIG. 7 is a diagram illustrating a fourth example of an optical imagingsystem.

FIG. 8 shows aberration curves of the optical imaging system illustratedin FIG. 7 .

FIG. 9 is a diagram illustrating a fifth example of an optical imagingsystem.

FIG. 10 shows aberration curves of the optical imaging systemillustrated in FIG. 9 .

FIG. 11 is a diagram illustrating a sixth example of an optical imagingsystem.

FIG. 12 shows aberration curves of the optical imaging systemillustrated in FIG. 11 .

FIG. 13 is a diagram illustrating a seventh example of an opticalimaging system.

FIG. 14 shows aberration curves of the optical imaging systemillustrated in FIG. 13 .

FIG. 15 is a diagram illustrating an eighth example of an opticalimaging system.

FIG. 16 shows aberration curves of the optical imaging systemillustrated in FIG. 15 .

FIG. 17 is a plan diagram illustrating a first lens according to anexample.

FIG. 18 is a plan diagram illustrating a gap maintaining member disposedbetween a first lens and a second lens of an optical imaging systemaccording to an example.

FIGS. 19, 20, 21, and 22 are rear side elevation diagrams illustrating aportable terminal device including an optical imaging system mountedthereon according to an example.

Throughout the drawings and the detailed description, the same referencenumerals refer to the same elements. The drawings may not be to scale,and the relative size, proportions, and depiction of elements in thedrawings may be exaggerated for clarity, illustration, and convenience.

DETAILED DESCRIPTION

The following detailed description is provided to assist the reader ingaining a comprehensive understanding of the methods, apparatuses,and/or systems described herein. However, various changes,modifications, and equivalents of the methods, apparatuses, and/orsystems described herein will be apparent to one of ordinary skill inthe art. The sequences of operations described herein are merelyexamples, and are not limited to those set forth herein, but may bechanged as will be apparent to one of ordinary skill in the art, withthe exception of operations necessarily occurring in a certain order.Also, descriptions of functions and constructions that would be wellknown to one of ordinary skill in the art may be omitted for increasedclarity and conciseness.

The features described herein may be embodied in different forms, andare not to be construed as being limited to the examples describedherein. Rather, the examples described herein have been provided so thatthis disclosure will be thorough and complete, and will fully convey thescope of the disclosure to one of ordinary skill in the art.

Herein, it is noted that use of the term “may” with respect to anexample or embodiment, e.g., as to what an example or embodiment mayinclude or implement, means that at least one example or embodimentexists in which such a feature is included or implemented while allexamples and embodiments are not limited thereto.

Throughout the specification, when an element, such as a layer, region,or substrate, is described as being “on,” “connected to,” or “coupledto” another element, it may be directly “on,” “connected to,” or“coupled to” the other element, or there may be one or more otherelements intervening therebetween. In contrast, when an element isdescribed as being “directly on,” “directly connected to,” or “directlycoupled to” another element, there can be no other elements interveningtherebetween.

As used herein, the term “and/or” includes any one and any combinationof any two or more of the associated listed items.

Although terms such as “first,” “second,” and “third” may be used hereinto describe various members, components, regions, layers, or sections,these members, components, regions, layers, or sections are not to belimited by these terms. Rather, these terms are only used to distinguishone member, component, region, layer, or section from another member,component, region, layer, or section. Thus, a first member, component,region, layer, or section referred to in examples described herein mayalso be referred to as a second member, component, region, layer, orsection without departing from the teachings of the examples.

Spatially relative terms such as “above,” “upper,” “below,” and “lower”may be used herein for ease of description to describe one element'srelationship to another element as shown in the figures. Such spatiallyrelative terms are intended to encompass different orientations of thedevice in use or operation in addition to the orientation depicted inthe figures. For example, if the device in the figures is turned over,an element described as being “above” or “upper” relative to anotherelement will then be “below” or “lower” relative to the other element.Thus, the term “above” encompasses both the above and below orientationsdepending on the spatial orientation of the device. The device may alsobe oriented in other ways (for example, rotated 90 degrees or at otherorientations), and the spatially relative terms used herein are to beinterpreted accordingly.

The terminology used herein is for describing various examples only, andis not to be used to limit the disclosure. The articles “a,” “an,” and“the” are intended to include the plural forms as well, unless thecontext clearly indicates otherwise. The terms “comprises,” “includes,”and “has” specify the presence of stated features, numbers, operations,members, elements, and/or combinations thereof, but do not preclude thepresence or addition of one or more other features, numbers, operations,members, elements, and/or combinations thereof.

Due to manufacturing techniques and/or tolerances, variations of theshapes shown in the drawings may occur. Thus, the examples describedherein are not limited to the specific shapes shown in the drawings, butinclude changes in shape that occur during manufacturing.

The features of the examples described herein may be combined in variousways as will be apparent after an understanding of the disclosure ofthis application. Further, although the examples described herein have avariety of configurations, other configurations are possible as will beapparent after an understanding of the disclosure of this application.

In the examples, a first lens refers to a lens most adjacent to anobject (or a subject), and a fourth lens refers to a lens most adjacentto an imaging plane (or an image sensor). In the examples, a unit of aradius of curvature, a thickness, a TTL, an IMG_HT (½ of a diagonallength of an imaging plane), and a focal length are indicated inmillimeters (mm). A thickness of a lens, a gap between lenses, and a TTLrefer to a distance of a lens in an optical axis. Also, in thedescriptions of a shape of a lens, the configuration in which onesurface is convex indicates that an optical axis region of the surfaceis convex, and the configuration in which one surface is concaveindicates that an optical axis region of the surface is concave. Thus,even when it is described that one surface of a lens is convex, an edgeof the lens may be concave. Similarly, even when it is described thatone surface of a lens is concave, an edge of the lens may be convex.

The optical imaging system includes an optical system including aplurality of lenses. For example, the optical system of the opticalimaging system may include a plurality of lenses having refractivepower. However, the optical imaging system does not only include lenseshaving refractive power. For example, the optical imaging system mayinclude a prism for refracting incident light and a stop for adjustingthe amount of light. The optical imaging system may also include aninfrared cut-off filter for blocking infrared rays. The optical imagingsystem may further include an image sensor (an imaging device)configured to convert an image of a subject incident through the opticalsystem into an electrical signal. The optical imaging system may furtherinclude a gap maintaining member for adjusting a distance betweenlenses.

The plurality of lenses may be formed of a material having a refractiveindex different from that of air. For example, the plurality of lensesmay be formed of a plastic or glass material. At least one of theplurality of lenses may have an aspherical shape. An aspherical surfaceof the lens may be represented by equation 1 as below.

$\begin{matrix}{Z = {\frac{{cr}^{2}}{1 + \sqrt{1 - {\left( {1 + k} \right)c^{2}r^{2}}}} + {Ar}^{4} + {Br}^{6} + {Cr}^{8} + {Dr}^{10} + {Er}^{12} + {Fr}^{14} + {Gr}^{16} + {Hr}^{18} + {Jr}^{20}}} & \left\lbrack {{Equation}1} \right\rbrack\end{matrix}$

In equation 1, “c” is an inverse of a radius of a curvature of arespective lens, “k” is a conic constant, “r” is a distance from acertain point on an aspherical surface of the lens to an optical axis,“A to J” are aspheric constants, “Z” (or SAG) is a height from a certainpoint on an aspherical surface of the lens to an apex of the asphericalsurface in an optical axis direction.

The optical imaging system may include four or more lenses. For example,the optical imaging system may include a first lens, a second lens, athird lens, and a fourth lens disposed in order from an object side.

The first to fourth lenses may be disposed with a gap between adjacentlenses. For example, an image-side surface of the first lens may not bein contact with an object-side surface of the second lens, and animage-side surface of the second lens may not be in contact with anobject-side surface of the third lens.

The first lens has a certain refractive power. For example, the firstlens may have positive refractive power. At least one surface of thefirst lens may be convex. For example, an object-side surface and animage-side surface of the first lens may be convex. The first lens mayhave a certain refractive index. For example, the first lens may have arefractive index equal to or higher than 1.5 and equal to or lower than1.6. The first lens may have a certain focal length. For example, afocal length of the first lens may be determined within a range of 3.4to 5.0 mm.

The second lens may have a certain refractive power. For example, thesecond lens may have negative refractive power. At least one surface ofthe second lens may be concave. For example, an object-side surface andan image-side surface of the second lens may be concave. The second lensmay have a certain refractive index. For example, the second lens mayhave a refractive index equal to or higher than 1.6 and equal to orlower than 2.0.

The third lens may have a certain refractive power. For example, thethird lens may have positive refractive power or negative refractivepower. One surface of the third lens may be convex. For example, anobject-side surface or an image-side surface of the third lens may beconcave. The third lens may have a certain refractive index. Forexample, the third lens may have a refractive index higher than that ofthe second lens.

The fourth lens may have a certain refractive power. For example, thefourth lens may have positive refractive power or negative refractivepower. One surface of the fourth lens may be convex. For example, animage-side surface of the fourth lens may be concave. The fourth lensmay have a certain refractive index. For example, the fourth lens mayhave a refractive index lower than that of the third lens.

An effective diameter of one or more of the first to fourth lenses in afirst direction intersecting an optical axis may have a shape differentfrom that of an effective diameter in a second direction. For example,an effective diameter of the first lens in a horizontal direction may bedifferent from an effective diameter of the first lens in a verticaldirection.

The optical imaging system may include a lens formed of a plasticmaterial. For example, in the optical imaging system, at least one ofthe four or more lenses included in a lens group may be formed of aplastic material.

The optical imaging system may include an aspherical lens. For example,in the optical imaging system, at least one of the four or more lensesincluded in a lens group may be configured as an aspherical lens.

The optical imaging system may include a member configured to fold orrefract an optical path. For example, the optical imaging system mayinclude a prism. The prism may be disposed on an object-side of thefirst lens. The prism may be formed of a material having a relativelylow Abbe number. For example, a material of the prism may be selectedfrom among materials having an Abbe number of 25 or lower.

The optical imaging system may include a filter, a stop, and an imagesensor.

The filter may be disposed between the fourth lens and the image sensor.The filter may improve resolution of the optical imaging system bypartially blocking a wavelength of incident light. For example, thefilter may block an infrared wavelength of incident light. The stop maybe disposed between the second lens and the third lens.

The optical imaging system may include a gap maintaining member.

The gap maintaining member may be disposed between lenses. For example,the gap maintaining member may be disposed between the first lens andthe second lens. A hole may be formed in a central portion of the gapmaintaining member. The hole may have a shape having a major axis and aminor axis. For example, the hole may have an oval shape, a rectangularshape with rounded corners, or the like. A length of a minor axis of thehole may have a size of 0.7 or higher and less than 1.0 as compared to alength of a major axis of the hole.

The optical imaging system may satisfy one or more of conditionalequations below.

0.1<L2R2/f<1.0  [Conditional Equation]

0.1<(L2R1+L2R2)/(L2R1−L2R2)<1.0  [Conditional Equation]

−5.0<L3R2/f<5.0  [Conditional Equation]

−10<(L3R1+L3R2)/(L3R1−L3R2)<10  [Conditional Equation]

1.0<f/f1<5.0  [Conditional Equation]

−5.0<f/f2<−1.0  [Conditional Equation]

−1.0<f/f3<3.0  [Conditional Equation]

−5.0<f/f4<5.0  [Conditional Equation]

−1.0<Nd1−Nd2<0  [Conditional Equation]

In the conditional equations, “L2R1” may be a radius of curvature of anobject-side surface of the second lens, “L2R2” may be a radius ofcurvature of an image-side surface of the second lens, “L3R1” may be aradius of curvature of an object-side surface of the third lens, “L3R2”may be a radius of curvature of an image-side surface of the third lens,“f” may be a focal length of the optical imaging system, “f1” is a focallength of the first lens, “f2” is a focal length of the second lens,“f3” is a focal length of the third lens, “f4” is focal length of thefourth lens, “Nd1” may be a refractive index of the first lens, and“Nd2” may be a refractive index of the second lens.

In addition, the optical imaging system may satisfy one or more ofconditional equations below.

4.0<f/IMG_HT<5.0  [Conditional Equation]

0.65<L1S1es/L1S1el<1.0  [Conditional Equation]

0.65<L1S2es/L1S2el<1.0  [Conditional Equation]

0.65<L2S1es/L2S1el<1.0  [Conditional Equation]

0.65<L2S2es/L2S2el<1.0  [Conditional Equation]

1.0 mm<DPL1<1.2 mm  [Conditional Equation]

11 mm<PTTL<15 mm  [Conditional Equation]

0.65<SPY2/SPX2<1.0  [Conditional Equation]

0.7<L1S1el/IMG_HT<0.9  [Conditional Equation]

0.10<L1S1el/PTTL<0.15  [Conditional Equation]

0.08<L1S1es/PTTL<0.11  [Conditional Equation]

0.09<L2S1el/PTTL<0.14  [Conditional Equation]

0.07<L2S1es/PTTL<0.10  [Conditional Equation]

0.03<AL1/(PTTL)²<0.06  [Conditional Equation]

80°<2θ<92°  [Conditional Equation]

3.0<2θ/FOV<5.0[Conditional Equation]

1.0<BFL/2IMG_HT<1.5  [Conditional Equation]

1.0<PTTL/f<2.0  [Conditional Equation]

In the conditional equations, “L1S1es” may be a minor-axis effectiveradius of an object-side surface of the first lens, “L1S1el” may be amajor-axis effective radius of the object-side surface of the firstlens, “L1S2es” may be a minor-axis effective radius of an image-sidesurface of the first lens, “L1S2el” may be a major-axis effective radiusof the image-side surface of the first lens, “L2S1es” may be aminor-axis effective radius of an object-side surface of the secondlens, “L2S1el” may be a major-axis effective radius of the object-sidesurface of the second lens, “L2S2es” may be a minor-axis effectiveradius of an image-side surface of the second lens, “L2S2el” may be amajor-axis effective radius of the image-side surface of the secondlens, “DPL1” may be a distance from an image-side surface of the prismto the object-side surface of the first lens, “PTTL” may be a distancefrom a reflective surface of the prism to an imaging plane, “SPY2” maybe a length of the hole formed in the gap maintaining member in a minoraxis direction, “SPX2” may be a length of the hole formed in the gapmaintaining member in a major axis direction, “AL1” may be an area of aneffective diameter of the first lens (an object-side surface) projectedon an imaging plane, “2θ” may be an angle formed by an a center of anoptical axis of a lens and both ends of a linear portion of an effectivediameter of a lens, “FOV” may be a field of view of the optical imagingsystem, and “BFL” may be a distance from an image-side surface of thelens disposed most adjacent to an imaging plane to the imaging plane.

In the description below, various examples of the optical imaging systemwill be described.

A first example of the optical imaging system will be described withreference to FIGS. 1 and 2 .

An optical imaging system 100 may include a prism P, a first lens 110, asecond lens 120, a third lens 130, and a fourth lens 140.

The first lens 110 may have positive refractive power, and may have aconvex object-side surface and a convex image-side surface. The secondlens 120 may have negative refractive power, and may have a concaveobject-side surface and a concave image-side surface. The third lens 130may have positive refractive power, and may have a convex object-sidesurface and a concave image-side surface. The fourth lens 140 may havepositive refractive power, and may have a convex object-side surface anda concave image-side surface.

The optical imaging system 100 may include the prism P, a filter 150,and an image sensor 160.

The optical imaging system 100 may include the prism P as a mechanismfor folding or refracting an optical path. The prism P may fold lightincident in a direction of a first optical axis C1 in a direction of asecond optical axis C2. The second optical axis C2 refracted by theprism P may be almost perpendicular to the first optical axis C1. Theprism P may be disposed on an object side of the first lens 110. Theprism P disposed as above may refract light reflected from an object (asubject) to the image sensor 160.

The filter 150 may be disposed in front of the image sensor 160 and mayblock infrared rays, or the like, included in incident light. The imagesensor 160 may include a plurality of optical sensors. The image sensor160 may be configured to convert an optical signal into an electricalsignal.

Table 1 lists characteristics of the lenses of the optical imagingsystem 100, and Table 2 lists aspherical values of the optical imagingsystem 100. FIG. 2 shows aberration curves of the optical imaging system100.

TABLE 1 Surface Radius of Thickness/ Focal Refractive Abbe No. NoteCurvature Gap Length Index Number  1 Prism infinity 1.6180 1.6349023.90000  2 infinity 1.6180 1.63490 23.90000  3 infinity 1.1326  4*First 2.6732 1.6500 4.1099 1.53500 56.00000  5* Lens −9.9574 0.0553  6*Second −28.9155 0.6289 −2.8694 1.61500 25.90000  7* Lens 1.9134 0.3819 8 Third 5.9194 0.9500 27.4657 1.67140 19.20000  9* Lens 8.1097 0.150010* Fourth 1.9845 0.6587 9.0000 1.61500 25.90000 11* Lens 2.6870 3.996612* Filter infinity 0.2427 1.54410 56.00000 13* infinity 1.0502 14Imaging infinity −0.0045 Plane

TABLE 2 Surface No. 4 5 6 7 8 9 10 11 K −1.77E−01  3.53E+01  5.06E+012.95E−01 1.95E+01 3.13E+01 −1.91E+00   1.97E+00 A  8.25E−04  1.27E−02−3.85E−02 −7.33E−02  3.11E−02 1.91E−02 −2.30E−02  −4.77E−02 B −1.28E−03−3.92E−03  2.52E−02 4.57E−02 −2.67E−02  −4.47E−03  5.09E−03 −6.00E−03 C 2.18E−03 −6.50E−03 −3.05E−03 −1.21E−02  2.69E−02 −6.41E−03  −8.91E−04  1.32E−02 D −3.25E−03  1.88E−02  3.11E−04 7.20E−03 −1.51E−02  1.83E−024.56E−03 −2.11E−02 E  2.21E−03 −1.85E−02  6.92E−04 −2.18E−03  1.85E−03−9.51E−03  −5.12E−03   1.58E−02 F −7.47E−04  1.27E−02 −3.71E−04 2.82E−030 −8.56E−03  1.76E−03 −4.42E−03 G  8.08E−05 −6.17E−03 −1.80E−04−6.57E−03  0 6.59E−03 3.33E−04  2.49E−12 H  1.58E−05  1.62E−03 −4.14E−052.79E−03 0 2.47E−15 0.00E+00 −2.12E−15 J −3.64E−06 −1.64E−04  4.13E−059.37E−14 0 1.22E−15 0.00E+00  1.89E−15

A second example of an optical imaging system will be described withreference to FIGS. 3 and 4 .

An optical imaging system 200 may include a prism P, a first lens 210, asecond lens 220, a third lens 230, and a fourth lens 240.

The first lens 210 may have positive refractive power, and may have aconvex object-side surface and a convex image-side surface. The secondlens 220 may have negative refractive power, and may have a concaveobject-side surface and a concave image-side surface. The third lens 230may have positive refractive power, and may have a convex object-sidesurface and a convex image-side surface. The fourth lens 240 may havenegative refractive power, and may have a convex object-side surface anda concave image-side surface.

The optical imaging system 200 may include the prism P, a filter 250,and an image sensor 260.

The optical imaging system may include the prism P as a mechanism forfolding or refracting an optical path. The prism P may fold lightincident in a direction of a first optical axis C1 in a direction of asecond optical axis C2. The second optical axis C2 refracted by theprism P may be almost perpendicular to the first optical axis C1. Theprism P may be disposed on an object side of the first lens 210. Theprism P disposed as above may refract light reflected from an object (asubject) to the image sensor 260.

The filter 250 may be disposed in front of the image sensor 260 and mayblock infrared rays, or the like, included in incident light. The imagesensor 260 may include a plurality of optical sensors. The image sensor260 may be configured to convert an optical signal into an electricalsignal.

Table 3 lists characteristics of the lenses of the optical imagingsystem 200, and Table 4 lists aspherical values of the optical imagingsystem 200. FIG. 4 shows aberration curves of the optical imaging system200.

TABLE 3 Surface Radius of Thickness/ Focal Refractive Abbe No. NoteCurvature Gap Length Index Number  1 Prism infinity 1.6180 1.6349023.90000  2 infinity 1.6180 1.63490 23.90000  3 infinity 1.1326  4*First 2.5334 1.6158 3.9065 1.53500 56.00000  5* Lens −9.5126 0.0488  6*Second −93.4595 0.6275 −2.9226 1.61500 25.90000  7* Lens 1.8544 0.4367 8 Third 8.4131 0.9500 9.6290 1.67140 19.20000  9* Lens −27.9766 0.150010* Fourth 4.0165 0.9500 −329.9551 1.61500 25.90000 11* Lens 3.58243.4830 12* Filter infinity 0.2427 1.54410 56.00000 13* infinity 1.070014 Imaging Plane infinity −0.0069

TABLE 4 Surface No. 4 5 6 7 8 9 10 11 K −1.28E−01  3.07E+01 −1.69E+018.33E−02 3.97E+01 9.10E+01 5.09E−01  2.71 E+00 A  1.23E−03  1.36E−02−4.32E−02 −8.54E−02  1.03E−03 1.99E−02 −1.65E−02  −3.05E−02 B −9.08E−04−3.22E−03  2.45E−02 5.41E−02 −8.08E−03  −2.22E−03  −6.41E−03  −7.01E−03C  2.18E−03 −6.90E−03 −2.47E−03 −8.48E−03  2.64E−02 −2.72E−03  8.32E−03 1.62E−02 D −3.25E−03  1.88E−02  2.50E−04 5.01E−03 −1.54E−02  2.12E−023.36E−03 −2.14E−02 E  2.22E−03 −1.85E−02  5.28E−04 −8.14E−04  3.28E−03−9.48E−03  −5.13E−03   1.58E−02 F −7.45E−04  1.28E−02 −4.00E−04 2.82E−030 −8.56E−03  1.76E−03 −4.42E−03 G  8.07E−05 −6.17E−03 −1.43E−04−6.57E−03  0 6.59E−03 3.33E−04  2.49E−12 H  1.56E−05  1.61E−03 −3.27E−052.79E−03 0 2.77E−15 0 −2.10E−15 J −3.62E−06 −1.64E−04  3.78E−05 9.37E−140 1.25E−15 0  1.92E−15

A third example of an optical imaging system will be described withreference to FIGS. 5 and 6 .

An optical imaging system 300 may include a prism P, a first lens 310, asecond lens 320, a third lens 330, and a fourth lens 340.

The first lens 310 may have positive refractive power, and may have aconvex object-side surface and a convex image-side surface. The secondlens 320 may have negative refractive power, and may have a concaveobject-side surface and a concave image-side surface. The third lens 330may have positive refractive power, and may have a convex object-sidesurface and a convex image-side surface. The fourth lens 340 may havenegative refractive power, and may have a convex object-side surface anda concave image-side surface.

The optical imaging system 300 may include the prism P, a filter 350,and an image sensor 360.

The optical imaging system may include the prism P as a mechanism forfolding or refracting an optical path. The prism P may fold lightincident in a direction of a first optical axis C1 in a direction of asecond optical axis C2. The second optical axis C2 refracted by theprism P may be almost perpendicular to the first optical axis C1. Theprism P may be disposed on an object side of the first lens 310. Theprism P disposed as above may refract light reflected from an object (asubject) to the image sensor 360.

The filter 350 may be disposed in front of the image sensor 360 and mayblock infrared rays, or the like, included in incident light. The imagesensor 360 may include a plurality of optical sensors. The image sensor360 may be configured to convert an optical signal into an electricalsignal.

Table 5 lists characteristics of the lenses of the optical imagingsystem 300, and Table 6 lists aspherical values of the optical imagingsystem 300. FIG. 6 shows aberration curves of the optical imaging system300.

TABLE 5 Surface Radius of Thickness/ Focal Refractive Abbe No. NoteCurvature Gap Length Index Number  1 Prism infinity 1.6180 1.6349023.90000  2 infinity 1.6180 1.63490 23.90000  3 infinity 1.1326  4*First 2.5090 1.6106 3.8768 1.53500 56.00000  5* Lens −9.5162 0.0580  6*Second −76.5761 0.6294 −3.0584 1.61500 25.90000  7* Lens 1.9524 0.4619 8 Third 13.3463 0.9500 8.4846 1.67140 19.20000  9* Lens −9.8419 0.103810* Fourth 5.3395 0.9500 −25.0000 1.61500 25.90000 11* Lens 3.70173.4487 12* Filter infinity 0.2427 1.54410 56.00000 13* infinity 1.070014 Imaging Plane infinity −0.0053

TABLE 6 Surface No. 4 5 6 7 8 9 10 11 K −1.07E−01  3.10E+01  9.90E+019.35E−02 7.62E+01 3.19E+00 1.09E+00  2.43E+00 A  1.54E−03  1.42E−02−4.37E−02 −8.61E−02  7.89E−05 2.07E−02 −1.66E−02  −3.46E−02 B −8.33E−04−3.04E−03  2.44E−02 5.72E−02 −2.08E−03  −4.20E−03  −9.60E−03  −5.09E−03C  2.21E−03 −7.01E−03 −2.28E−03 −7.78E−03  2.72E−02 −4.99E−03  4.46E−03 1.43E−02 D −3.24E−03  1.87E−02  2.48E−04 5.85E−03 −1.67E−02  2.26E−026.16E−03 −2.07E−02 E  2.22E−03 −1.85E−02  4.71E−04 −1.38E−03  4.39E−03−9.48E−03  −5.13E−03   1.58E−02 F −7.45E−04  1.28E−02 −4.27E−04 2.82E−030 −8.56E−03  1.76E−03 −4.42E−03 G  8.06E−05 −6.17E−03 −1.42E−04−6.57E−03  0 6.59E−03 3.33E−04  2.48E−12 H  1.55E−05  1.61E−03 −2.62E−052.79E−03 0 2.03E−15 0 −2.91E−15 J −3.59E−06 −1.64E−04  3.81E−05 9.36E−140 1.11E−15 0  1.77E−15

A fourth example of an optical imaging system will be described withreference to FIGS. 7 and 8 .

An optical imaging system 400 may include a prism P, a first lens 410, asecond lens 420, a third lens 430, and a fourth lens 440.

The first lens 410 may have positive refractive power, and may have aconvex object-side surface and a convex image-side surface. The secondlens 420 may have negative refractive power, and may have a concaveobject-side surface and a concave image-side surface. The third lens 430may have positive refractive power, and may have a concave object-sidesurface and a convex image-side surface. The fourth lens 440 may havenegative refractive power, and may have a convex object-side surface anda concave image-side surface.

The optical imaging system 400 may include the prism P, a filter 450,and an image sensor 460.

The optical imaging system may include the prism P as a mechanism forfolding or refracting an optical path. The prism P may fold lightincident in a first optical axis C1 direction in a direction of a secondoptical axis C2. The second optical axis C2 refracted by the prism P maybe almost perpendicular to the first optical axis C1. The prism P may bedisposed on an object side of the first lens 410. The prism P disposedas above may refract light reflected from an object (a subject) to theimage sensor 460.

The filter 450 may be disposed in front of the image sensor 460 and mayblock infrared rays, or the like, included in incident light. The imagesensor 460 may include a plurality of optical sensors. The image sensor460 may be configured to convert an optical signal into an electricalsignal.

Table 7 lists characteristics of the lenses of the optical imagingsystem 400, and Table 8 lists aspherical values of the optical imagingsystem 400. FIG. 8 shows aberration curves of the optical imaging system400.

TABLE 7 Surface Radius of Thickness/ Focal Refractive Abbe No. NoteCurvature Gap Length Index Number  1 Prism infinity 1.6180 1.6349023.90000  2 infinity 1.6180 1.63490 23.90000  3 infinity 1.1326  4*First 2.5066 1.5952 3.8632 1.53500 56.00000  5* Lens −9.3886 0.0527  6*Second −133.027 0.6200 −3.4934 1.61500 25.90000  7* Lens 2.2079 0.5050 8 Third −81.2138 0.9500 7.3982 1.67140 19.20000  9* Lens −4.7524 0.116710* Fourth 13.6238 0.9500 −10.0000 1.61500 25.90000 11* Lens 4.14993.4015 12* Filter infinity 0.2427 1.54410 56.00000 13* infinity 1.070014 Imaging Plane infinity −0.0038

TABLE 8 Surface No. 4 5 6 7 8 9 10 11 K −9.02E−02  3.15E+01 −9.90E+011.87E−01 9.90E+01 2.02E+00 −6.30E+01  1.22E+00 A  1.98E−03  1.46E−02−4.42E−02 −8.36E−02  −9.10E−04  2.17E−02 −1.98E−02 −3.85E−02 B −8.07E−04−2.89E−03  2.42E−02 5.82E−02 1.59E−03 −4.88E−03  −1.20E−02 −2.55E−03 C 2.19E−03 −7.04E−03 −2.20E−03 −9.18E−03  2.78E−02 −5.05E−03   5.07E−03 1.52E−02 D −3.24E−03  1.87E−02  2.69E−04 5.94E−03 −1.72E−02  2.38E−02 7.11E−03 −2.13E−02 E  2.22E−03 −1.85E−02  4.62E−04 −3.98E−04  5.23E−03−9.48E−03  −5.13E−03  1.58E−02 F −7.45E−04  1.28E−02 −4.33E−04 2.82E−030 −8.56E−03   1.76E−03 −4.42E−03 G  8.05E−05 −6.16E−03 −1.43E−04−6.57E−03  0 6.59E−03  3.33E−04  2.48E−12 H  1.55E−05  1.61E−03−2.53E−05 2.79E−03 0 1.99E−15 0 −2.92E−15 J −3.59E−06 −1.64E−04 3.86E−05 9.36E−14 0 1.11E−15 0  1.77E−15

A fifth example of an optical imaging system will be described withreference to FIGS. 9 and 10 .

An optical imaging system 500 may include a prism P, a first lens 510, asecond lens 520, a third lens 530, and a fourth lens 540.

The first lens 510 may have positive refractive power, and may have aconvex object-side surface and a convex image-side surface. The secondlens 520 may have negative refractive power, and may have a concaveobject-side surface and a concave image-side surface. The third lens 530may have positive refractive power, and may have a concave object-sidesurface and a convex image-side surface. The fourth lens 540 may havenegative refractive power, and may have a concave object-side surfaceand a concave image-side surface.

The optical imaging system 500 may include the prism P, a filter 550,and an image sensor 560.

The optical imaging system may include the prism P as a mechanism forfolding or refracting an optical path. The prism P may fold lightincident in a direction of a first optical axis C1 in a direction of asecond optical axis C2. The second optical axis C2 refracted by theprism P may be almost perpendicular to the first optical axis C1. Theprism P may be disposed on an object side of the first lens 510. Theprism P disposed as above may refract light reflected from an object (asubject) to the image sensor 560.

The filter 550 may be disposed in front of the image sensor 560 and mayblock infrared rays, or the like, included in incident light. The imagesensor 560 may include a plurality of optical sensors. The image sensor560 may be configured to convert an optical signal into an electricalsignal.

Table 9 lists characteristics of the lenses of the optical imagingsystem 500, and Table 10 lists aspherical values of the optical imagingsystem 500. FIG. 10 shows aberration curves of the optical imagingsystem 500.

TABLE 9 Surface Radius of Thickness/ Focal Refractive Abbe No. NoteCurvature Gap Length Index Number  1 Prism infinity 1.6180 1.6349023.90000  2 infinity 1.6180 1.63490 23.90000  3 infinity 1.1326  4*First 2.5079 1.5845 3.8497 1.53500 56.00000  5* Lens −9.1988 0.0461  6*Second −118.740 0.6200 −4.3132 1.61500 25.90000  7* Lens 2.7440 0.5769 8 Third −7.5014 0.9500 6.4488 1.67140 19.20000  9* Lens −2.9061 0.127610* Fourth −9.9496 0.9500 −6.0001 1.61500 25.90000 11* Lens 6.16823.3503 12* Filter infinity 0.2427 1.54410 56.00000 13* infinity 1.050014 Imaging Plane infinity 0.0019

TABLE 10 Surface No. 4 5 6 7 8 9 10 11 K −7.01E−02  3.17E+01 −9.90E+012.41E−01 1.58E+01 1.29E+00 2.80E+01 9.09E−02 A  2.41E−03  1.45E−02−4.43E−02 −8.39E−02  −7.91E−03  2.84E−02 −2.69E−02  −4.16E−02  B−7.18E−04 −2.67E−03  2.39E−02 5.98E−02 9.71E−03 −7.15E−03  −1.59E−02 9.08E−04 C  2.15E−03 −7.14E−03 −2.00E−03 −1.09E−02  2.76E−02 −3.68E−03 1.99E−03 1.32E−02 D −3.24E−03  1.87E−02  3.62E−04 5.46E−03 −1.94E−02 2.27E−02 8.55E−03 −2.08E−02  E  2.22E−03 −1.85E−02  4.64E−04 1.12E−036.66E−03 −9.48E−03  −5.13E−03  1.58E−02 F −7.45E−04  1.28E−02 −4.46E−042.82E−03 0 −8.56E−03  1.76E−03 −4.42E−03  G  8.04E−05 −6.16E−03−1.50E−04 −6.57E−03  0 6.59E−03 3.33E−04 2.48E−12 H  1.54E−05  1.62E−03−2.55E−05 2.79E−03 0 1.81E−15 0 −2.93E−15  J −3.60E−06 −1.63E−04 4.07E−05 9.36E−14 0 1.09E−15 0 1.76E−15

A sixth example of an optical imaging system will be described withreference to FIGS. 11 and 12 .

An optical imaging system 600 may include a prism P, a first lens 610, asecond lens 620, a third lens 630, and a fourth lens 640.

The first lens 610 may have positive refractive power, and may have aconvex object-side surface and a convex image-side surface. The secondlens 620 may have negative refractive power, and may have a concaveobject-side surface and a concave image-side surface. The third lens 630may have positive refractive power, and may have a convex object-sidesurface and a convex image-side surface. The fourth lens 640 may havepositive refractive power, and may have a convex object-side surface anda concave image-side surface.

The optical imaging system 600 may include the prism P, a filter 650,and an image sensor 660.

The optical imaging system may include the prism P as a mechanism forfolding or refracting an optical path. The prism P may fold lightincident in a direction of a first optical axis C1 in a direction of asecond optical axis C2. The second optical axis C2 refracted by theprism P may be almost perpendicular to the first optical axis C1. Theprism P may be disposed on an object side of the first lens 610. Theprism P disposed as above may refract light reflected from an object (asubject) to the image sensor 660.

The filter 650 may be disposed in front of the image sensor 660 and mayblock infrared rays, or the like, included in incident light. The imagesensor 660 may include a plurality of optical sensors. The image sensor660 may be configured to convert an optical signal into an electricalsignal.

Table 11 lists characteristics of the lenses of the optical imagingsystem 600, and Table 12 lists aspherical values of the optical imagingsystem 600. FIG. 12 shows aberration curves of the optical imagingsystem 600.

TABLE 11 Surface Radius of Thickness/ Focal Refractive Abbe No. NoteCurvature Gap Length Index Number  1 Prism infinity 1.5440 1.6349023.90000  2 infinity 1.5440 1.63490 23.90000  3 infinity 1.1194  4*First 2.4809 1.2410 3.8330 1.53500 56.00000  5* Lens −10.0050 0.2107  6*Second −5.9163 0.6414 −2.8632 1.61500 25.90000  7* Lens 2.6451 0.3611  8Third 32.2309 0.7720 16.7347 1.67140 19.20000  9* Lens −17.3757 0.061810* Fourth 2.1068 0.5981 16.5768 1.61500 25.90000 11* Lens 2.3614 4.310012* Filter infinity 0.2100 1.54410 56.00000 13* infinity 1.1618 14Imaging Plane infinity 0.0016

TABLE 12 Surface No. 4 5 6 7 8 9 10 11 K 0.00E+00 0.00E+00  0.00E+00 0.00E+00 0.00E+00  0.00E+00  0.00E+00  0.00E+00 A 1.15E−03 1.80E−02−1.14E−02 −6.40E−02 2.64E−02 −2.06E−02 −1.25E−01 −6.87E−02 B −1.43E−04 −3.31E−03   1.75E−02  3.66E−02 −2.66E−02  −6.54E−03 −1.10E−02 −3.26E−02C 1.36E−03 8.52E−04 −3.01E−03 −8.99E−03 7.11E−03 −8.22E−03 −6.19E−03 3.18E−02 D −1.60E−03  6.83E−04 −8.68E−04 −1.67E−03 −3.65E−03   8.05E−03 1.41E−02 −1.13E−02 E 9.08E−04 −5.05E−06   1.87E−04 −1.71E−03 2.89E−04−2.00E−03 −4.63E−03  1.41E−03 F −2.46E−04  −3.03E−04  −3.58E−06 1.55E−03 0 0 0 0 G 2.60E−05 8.39E−05  1.61E−05 −3.18E−04 0 0 0 0 H 0 00 0 0 0 0 0 J 0 0 0 0 0 0 0 0

A seventh example of an optical imaging system will be described withreference to FIGS. 13 and 14 .

An optical imaging system 700 may include a prism P, a first lens 710, asecond lens 720, a third lens 730, and a fourth lens 740.

The first lens 710 may have positive refractive power, and may have aconvex object-side surface and a convex image-side surface. The secondlens 720 may have negative refractive power, and may have a concaveobject-side surface and a concave image-side surface. The third lens 730may have negative refractive power, and may have a concave object-sidesurface and a convex image-side surface. The fourth lens 740 may havepositive refractive power, and may have a convex object-side surface anda concave image-side surface.

The optical imaging system 700 may include the prism P, a filter 750,and an image sensor 760.

The optical imaging system may include the prism P as a mechanism forfolding or refracting an optical path. The prism P may fold lightincident in a direction of a first optical axis C1 in a direction of asecond optical axis C2. The second optical axis C2 refracted by theprism P may be almost perpendicular to the first optical axis C1. Theprism P may be disposed on an object side of the first lens 710. Theprism P may refract light reflected from an object (a subject) to theimage sensor 760.

The filter 750 may be disposed in front of the image sensor 760 and mayblock infrared rays, or the like, included in incident light. The imagesensor 760 may include a plurality of optical sensors. The image sensor760 may be configured to convert an optical signal into an electricalsignal.

Table 13 lists characteristics of the lenses of the optical imagingsystem 700, and Table 14 lists aspherical values of the optical imagingsystem 700. FIG. 14 is aberration curves of the optical imaging system700.

TABLE 13 Surface Radius of Thickness/ Focal Refractive Abbe No. NoteCurvature Gap Length Index Number  1 Prism infinity 1.5440 1.6349023.90000  2 infinity 1.5440 1.63490 23.90000  3 infinity 1.1194  4*First 3.0000 1.4000 4.3547 1.53500 56.00000  5* Lens −8.8982 0.1481  6*Second −250.000 0.6926 −4.2453 1.61500 25.90000  7* Lens 2.6655 0.3965 8 Third −6.9257 0.9734 −51.3113 1.67140 19.20000  9* Lens −9.13550.0400 10* Fourth 2.1000 0.7968 13.1062 1.61500 25.90000 11* Lens 2.41964.0062 12* Filter infinity 0.2100 1.54410 56.00000 13* infinity 1.160014 Imaging Plane infinity −0.0030

TABLE 14 Surface No. 4 5 6 7 8 9 10 11 K −1.80E−01 2.51E+01  9.90E+01−3.91E−01 −5.21E+01 −7.28E+01  4.26E−01 5.09E−01 A  1.33E−03 1.82E−02−3.21E−02 −6.60E−02  4.71E−02 −1.08E−02 −1.12E−01 −6.67E−02  B −1.20E−03−5.52E−03   1.43E−02  3.87E−02 −2.66E−02 −2.08E−03 −3.72E−03 −1.63E−02 C  1.44E−03 7.08E−04 −1.97E−03 −1.20E−02  1.38E−02 −5.87E−03 −6.78E−031.55E−02 D −1.72E−03 5.84E−04 −4.48E−04 −5.44E−04 −7.76E−03  6.23E−03 8.26E−03 −5.31E−03  E  9.06E−04 7.92E−05  1.23E−04 −2.21E−03 −4.38E−04−2.48E−03 −3.12E−03 1.72E−04 F −2.35E−04 −2.36E−04  −5.25E−05  1.26E−03 8.55E−04  7.56E−05  2.47E−05 1.52E−04 G  2.32E−05 6.13E−05  3.04E−05 0.00E+00  1.10E−05  9.39E−05  5.47E−13 6.41E−13 H 0 0 0 0 0 0 0 0 J 0 00 0 0 0 0 0

An eighth example of an optical imaging system will be described withreference to FIGS. 15 and 16 .

An optical imaging system 800 may include a first prism P1, a first lens810, a second lens 820, a third lens 830, and a fourth lens 840.

The first lens 810 may have positive refractive power, and may have aconvex object-side surface and a convex image-side surface. The secondlens 820 may have negative refractive power, and may have a concaveobject-side surface and a concave image-side surface. The third lens 830may have positive refractive power, and may have a convex object-sidesurface and a convex image-side surface. The fourth lens 840 may havepositive refractive power, and may have a convex object-side surface anda concave image-side surface.

The optical imaging system 800 may include the first prism P1, a filter850, a second prism P2, and an image sensor 860.

The optical imaging system may include the first prism P1 as a mechanismfor folding or refracting an optical path. The first prism P1 may foldlight incident in a direction of a first optical axis C1 in a directionof a second optical axis C2. The second optical axis C2 refracted by thefirst prism P1 may be almost perpendicular to the first optical axis C1.The first prism P1 may be disposed on an object side of the first lens810. The first prism P1 may refract light reflected from an object (asubject) to the second prism P2. The second prism P2 may refract theincident light to the image sensor 860.

The filter 850 may be disposed in front of the image sensor 860 and mayblock infrared rays, or the like, included in incident light. The imagesensor 860 may include a plurality of optical sensors. The image sensor860 may be configured to convert an optical signal into an electricalsignal.

Table 15 lists characteristics of the lenses of the optical imagingsystem 800, and Table 16 lists aspherical values of the optical imagingsystem 800. FIG. 16 is aberration curves of the optical imaging system800.

TABLE 15 Surface Radius of Thickness/ Focal Refractive Abbe No. NoteCurvature Gap Length Index Number  1 First infinity 1.5440 1.6349 23.9 2 Prism infinity 1.5440 1.6349 23.9  3 infinity 1.1194  4* First 2.48101.2410 3.8330 1.535 56  5* Lens −10.0050 0.2107  6* Second −5.91600.6414 −2.8632 1.615 25.9  7* Lens 2.6450 0.3611  8 Third 32.2310 0.772016.7347 1.6714 19.2  9* Lens −17.3760 0.0618 10* Fourth 2.1070 0.598116.5768 1.615 25.9 11* Lens 2.3610 2.0000 12 Second infinity 1.50001.6349 23.9 13 Prism infinity 1.5000 1.6349 23.9 14 infinity 1.5000 15*Filter infinity 0.2100 1.5441 56 16* infinity 1.1618 17 Imaging Planeinfinity 0.0016

TABLE 16 Surface No. 4 5 6 7 8 9 10 11 K 0 0 0 0 0 0 0 0 A 1.152E−031.800E−02 −1.140E−02 −6.400E−02 2.640E−02 −2.060E−02 −1.250E−01−6.870E−02 B −1.430E−04  −3.310E−03   1.750E−02  3.660E−02 −2.660E−02 −6.540E−03 −1.100E−02 −3.260E−02 C 1.364E−03 8.520E−04 −3.006E−03−8.991E−03 7.106E−03 −8.224E−03 −6.192E−03  3.180E−02 D −1.596E−03 6.826E−04 −8.678E−04 −1.666E−03 −3.650E−03   8.051E−03  1.406E−02−1.133E−02 E 9.084E−04 −5.050E−06   1.867E−04 −1.713E−03 2.892E−04−2.003E−03 −4.630E−03  1.413E−03 F −2.456E−04  −3.032E−04  −3.580E−06 1.548E−03 0 0 0 0 G 2.600E−05 8.390E−05  1.610E−05 −3.180E−04 0 0 0 0 H0 0 0 0 0 0 0 0 J 0 0 0 0 0 0 0 0

Table 17 lists optical properties of the optical imaging system of thefirst to seventh examples.

TABLE 17 Example f f-number IMG_HT FOV 2θ AL1 BFL TTL PTTL 1 9.70 2.802.04 23.48 91.15 7.285 5.285 9.760 12.510 2 9.70 2.80 2.04 23.34 91.157.285 4.789 9.568 12.318 3 9.70 2.80 2.04 23.32 91.15 7.285 4.756 9.52012.271 4 9.71 2.80 2.04 23.30 91.15 7.285 4.710 9.500 12.251 5 9.71 2.802.04 23.36 91.15 7.285 4.645 9.500 12.251 6 9.66 2.80 2.04 23.28 91.157.371 5.683 9.569 12.233 7 9.50 2.80 2.04 23.66 91.15 7.371 5.373 9.82112.484

Table 18 lists a major-axis effective radius [mm] of the lenses of eachexample, and FIG. 19 lists a minor-axis effective radius [mm] of thelenses of each example.

TABLE 18 Example L1S1el L1S2el L2S1el L2S2el L3S1el L3S2el L4S1el L4S2el1 1.690 1.494 1.433 1.168 1.200 1.042 1.020 1.037 2 1.690 1.470 1.4111.141 1.200 1.050 1.020 1.081 3 1.690 1.470 1.412 1.142 1.200 1.0541.020 1.075 4 1.690 1.472 1.413 1.149 1.200 1.061 1.020 1.125 5 1.6901.487 1.427 1.172 1.200 1.087 1.020 1.150 6 1.700 1.533 1.488 1.2511.221 1.246 1.205 1.200 7 1.700 1.553 1.473 1.270 1.241 1.259 1.2201.200

TABLE 19 Example L1S1es L1S2es L2S1es L2S2es L3S1es L3S2es L4S1es L4S2es1 1.183 1.046 1.003 0.818 0.840 0.730 0.714 0.726 2 1.183 1.029 0.9880.799 0.840 0.735 0.714 0.756 3 1.183 1.029 0.988 0.800 0.840 0.7380.714 0.753 4 1.183 1.031 0.989 0.805 0.840 0.743 0.714 0.787 5 1.1831.041 0.999 0.821 0.840 0.761 0.714 0.805 6 1.190 1.073 1.042 0.8760.854 0.872 0.843 0.840 7 1.190 1.087 1.031 0.889 0.869 0.881 0.8540.840

Tables 20 to 22 list values of conditional equations of the opticalimaging systems of the first to seventh examples. As indicated in Tables20 to 22, the optical imaging systems of the first to seventh examplesmay satisfy the aforementioned conditional equations.

TABLE 20 Conditional First Second Third Fourth Fifth Sixth SeventhEighth Equation Example Example Example Example Example Example ExampleExample L2R2/f 0.1973 0.1912 0.2013 0.2274 0.2826 0.2738 0.2806 0.2738(L2R1 + L2R2)/ 0.8759 0.9611 0.9503 0.9673 0.9548 0.3821 0.9789 0.3821(L2R1 − L2R2) L3R2/f 0.8361 −2.8842 −1.0146 −0.4894 −0.2993 −1.7987−0.9616 −1.7987 (L3R1 + L3R2)/ −6.4050 −0.5376 0.1511 1.1243 2.26480.2995 −7.2679 0.2995 (L3R1 − L3R2) f/f1 2.3602 2.4830 2.5021 2.51352.5223 2.5202 2.1816 2.5202 f/f2 −3.3805 −3.3190 −3.1716 −2.7795 −2.2512−3.3738 −2.2378 −3.3738 f/f3 0.3532 1.0074 1.1433 1.3125 1.5057 0.5772−0.1851 0.5772 f/f4 1.0779 −0.0294 −0.3880 −0.9710 −1.6183 0.5827 0.72490.5827 Nd1 − Nd2 −0.0800 −0.0800 −0.0800 −0.0800 −0.0800 −0.0800 −0.0800−0.0800

TABLE 21 Conditional First Second Third Fourth Fifth Sixth SeventhEquation Example Example Example Example Example Example ExampleL1S1es/L1S1el 0.7000 0.7000 0.7000 0.7000 0.7000 0.7000 0.7000L1S2es/L1S2el 0.7000 0.7000 0.7000 0.7000 0.7000 0.7000 0.7000L2S1es/L2S1el 0.7000 0.7000 0.7000 0.7000 0.7000 0.7000 0.7000L2S2es/L2S2el 0.7000 0.7000 0.7000 0.7000 0.7000 0.7000 0.7000 DPL11.1326 1.1326 1.1326 1.1326 1.1326 1.1194 1.1194 SPY2/SPX2 0.7000 0.70000.7000 0.7000 0.7000 0.7000 0.7000 L1S1el/IMG_HT 0.8284 0.8284 0.82840.8284 0.8284 0.8333 0.8333

TABLE 22 Conditional First Second Third Fourth Fifth Sixth SeventhEquation Example Example Example Example Example Example ExampleL1S1el/PTTL 0.1351 0.1372 0.1377 0.1380 0.1380 0.1390 0.1362 L1S1es/PTTL0.0946 0.0960 0.0964 0.0966 0.0966 0.0973 0.0953 L2S1el/PTTL 0.11460.1146 0.1150 0.1154 0.1165 0.1217 0.1180 L2S1es/PTTL 0.0802 0.08020.0805 0.0807 0.0816 0.0852 0.0826 AL1/(PTTL)² 0.0465 0.0480 0.04840.0485 0.0485 0.0493 0.0473 2θ/FOV 3.8819 3.9051 3.9085 3.9118 3.90183.9152 3.8523 BFL/2IMG_HT 1.2953 1.1737 1.1657 1.1545 1.1385 1.39301.3170

The optical imaging system of the examples may include the lens and agap maintaining member illustrated in FIGS. 17 and 18 . FIG. 17illustrates only the configuration of the first lens, but the second tofourth lenses may also be configured as in the example illustrated inFIG. 17 .

Lengths of the first lens L1 in the first direction and the seconddirection, intersecting an optical axis, may be configured to bedifferent from each other. For example, an effective radius (L1S1el;hereinafter, a major-axis effective radius) of the first lens L1 in thefirst direction may be greater than an effective radius (L1S1es;hereinafter, a minor-axis effective radius) in the second direction. Onesurface of the first lens L1 may be configured to be linear. Forexample, both side surfaces of the first lens L1 in parallel to themajor-axis effective radius may be configured to be linear asillustrated in FIG. 17 . A range of a size of the linear portion of thefirst lens L1 may be limited to a certain size. For example, an angle 28formed by an optical axis center C2 of the first lens L1 and both endsof the linear portion may be selected from a range of 80 to 92 degrees.

The gap maintaining member SP may be configured to be almost rectangularas illustrated in FIG. 18 . For example, a length SPX1 of the gapmaintaining member SP in the first direction may be greater than alength SPY1 in the second direction. A hole of the gap maintainingmember SP may have a shape of an effective diameter of the lens, a shapethe same as or similar to the shape of the effective diameter. The holeof the gap maintaining member SP in the example embodiment may be formedby a pair of linear lines parallel to each other and a pair of curvedlines, as illustrated in FIG. 18 . A length SPX2 of the hole of the gapmaintaining member SP in the first direction may be greater than alength SPY2 in the second direction.

An optical imaging system 20 in the example may be mounted on asmall-sized terminal device. For example, one or more of the opticalimaging systems described in the aforementioned examples may be mountedon a rear surface or a front surface of a small-sized terminal device 10as illustrated in FIGS. 19 to 22 .

The small-sized terminal device 10 may include a plurality of opticalimaging systems 20, 30, 40, and 50. As an example, the small-sizedterminal device 10 may include the optical imaging system 20 for imagingan object at a long distance and the optical imaging system 30 forimaging an object at a short distance as illustrated in FIG. 19 . Asanother example, the small-sized terminal device 10 may include theoptical imaging system 20 for imaging an object in a long distance andthe two optical imaging systems 30 and 40 for imaging an object in ashort distance as illustrated in FIG. 20 . As another example, thesmall-sized terminal device 10 may include the optical imaging system 20for imaging an object in a long distance and the optical imaging systems30, 40, and 50 having different focal lengths.

An arrangement form of the optical imaging systems 20, 30, 40, and 50may be varied as illustrated in FIGS. 19 to 22 .

According to the aforementioned examples, the optical imaging systemwhich may have a relatively long focal length and may be mountable on asmall-sized terminal device may be implemented.

While this disclosure includes specific examples, it will be apparentafter an understanding of the disclosure of this application thatvarious changes in forms and details may be made in these exampleswithout departing from the spirit and scope of the claims and theirequivalents. The examples described herein are to be considered in adescriptive sense only, and not for purposes of limitation. Descriptionsof features or aspects in each example are to be considered as beingapplicable to similar features or aspects in other examples. Suitableresults may be achieved if the described techniques are performed in adifferent order, and/or if components in a described system,architecture, device, or circuit are combined in a different manner,and/or replaced or supplemented by other components or theirequivalents. Therefore, the scope of the disclosure is defined not bythe detailed description, but by the claims and their equivalents, andall variations within the scope of the claims and their equivalents areto be construed as being included in the disclosure.

What is claimed is:
 1. An optical imaging system, comprising: a prism afirst lens comprising positive refractive power; a second lenscomprising negative refractive power; a third lens comprising positiverefractive power; and a fourth lens comprising positive refractivepower, wherein the prism and the first to fourth lenses are sequentiallydisposed in order from an object side to an image plane, wherein theoptical imaging system has a total number of four lenses, and wherein1.0<PTTL/f<2.0, where PTTL is a distance from the reflective surface ofthe prism to the imaging plane and f is a focal length of the opticalimaging system.
 2. The optical imaging system of claim 1, wherein thefirst lens has a convex object-side surface.
 3. The optical imagingsystem of claim 1, wherein the first lens has a convex image-sidesurface.
 4. The optical imaging system of claim 1, wherein the secondlens has a concave image-side surface.
 5. The optical imaging system ofclaim 1, wherein the third lens has a convex object-side surface.
 6. Theoptical imaging system of claim 1, wherein the fourth lens has a convexobject-side surface.
 7. The optical imaging system of claim 1, whereinthe fourth lens has a concave image-side surface.
 8. The optical imagingsystem of claim 1, wherein 0.10<L2R2/f<1.0, where L2R2 is a radius ofcurvature of an image-side surface of the second lens.
 9. The opticalimaging system of claim 1, wherein −5.0<L3R2/f<5.0, where L3R2 is aradius of curvature of an image-side surface of the third lens.
 10. Theoptical imaging system of claim 1, wherein−10<(L3R1+L3R2)/(L3R1−L3R2)<10, where L3R1 is a radius of curvature ofan object-side surface of the third lens, and L3R2 is a radius ofcurvature of an image-side surface of the third lens.
 11. The opticalimaging system of claim 1, wherein 1.0<f/f1<5.0, where f1 is a focallength of the first lens.
 12. The optical imaging system of claim 1,wherein −5.0<f/f2<−1.0, where f2 is a focal length of the second lens.13. The optical imaging system of claim 1, wherein −1.0<f/f3<3.0, wheref3 is a focal length of the third lens.
 14. The optical imaging systemof claim 1, wherein −5.0<f/f4<5.0, f4 is a focal length of the fourthlens.
 15. The optical imaging system of claim 1, wherein −1.0<Nd1−Nd2<0,where Nd1 is a refractive index of the first lens and Nd2 is arefractive index of the second lens.
 16. An optical imaging system,comprising: a prism a first lens comprising positive refractive power; asecond lens comprising a refractive power; a third lens comprisingpositive refractive power and convex image-side surface; and a fourthlens comprising positive refractive power, wherein the prism and thefirst to fourth lenses are sequentially disposed in order from an objectside to an image plane, wherein the optical imaging system has a totalnumber of four lenses, and wherein 1.0<PTTL/f<2.0, where PTTL is adistance from the reflective surface of the prism to the imaging planeand f is a focal length of the optical imaging system.